Tensiometer



June 6,1944. HJ, SANG 2,350,419

TENSIOMETER Filed May 26,' 1942 2 Sheets-Sheet l INVENTOR:

Ear JSa June 6, 1944. H. 'J, SANG TENSIOMETER Filed May 26, 1942 2 Sheets-Sheet 2 INVENTOR .5210" .1152? lax g f ATT 0k/$EY% Patented June 6, 1944 UNITED STATES PATENT-OFFICE TENSIOMETER' Henry J. Sang, Moylan, Pa.

Application May 26, 1942, Serial No. 444,599

9 Claims.

This invention relates to tensiometers, and particularly to devices for measuring the tension in wires, cables, guy wires, stays, and the like.

There are many situations in the arts in which the exact tensioning of cables and the lik is material to the safety of the device and its operators. Specifically, for instance, the control cables as well as rigging wires in aircraft need to be maintained in very exact predetermined tension for the utmost in safety. It is desirable that the instrumentality for securing such measurement be small and light in order to be insertable into and operable within small inspection openings, that the proper and efficient use of the instrument be by a movement of a single hand of the operator, that the recording of the exact tension be automatic and that the determination of the tension of the cable be exact regardless of the particular diameter or elasticity of the instant cable or the like being tested, designated as the deflection characteristics, and that it be susceptible to useupon various sizes of wires or cables with maintained accuracy.

It is among the objects of this invention; to provide a tension meter possessed of all of the above described attributes; to produce an instrument for exact measurements of tension vin contrast to the mere approximations of tension obtained with the prior art; to produce a portable instrument of extreme'lightness and compactness without sacrifice of efficiency; to provide a tension meter which measures the tension of a cord or cable solely by the measurement of the deflection of an elastic member deflected by the tension of the cables, which obviates the potential variations in tension reading arising from friction about pivots and the like in other devices for similar purposes; to provide a novel device for measuring the tension of taut wires, cables and the like; to provide a tension meter by which the tension of various sizes of cables may be determined without resort to calibration tables or charts; to provide a tension meter by which a tension reading is obtainable with a single'motion of th hand; to improve the art of tensiometers; to provide in a single-instrument a device for testing tensions of cables having various determined deflecting characteristics; and many other objects and advantages will become more apparent as the description proceeds.

In carrying out the invention in a preferred embodiment an elastic deflection beamor the like is provided which is loaded by forcing it the free end of the beam, with a calibrated agency operative to measure the deflection of the beam as a result of beam loading only without regard to friction in pivots and the lik as a function of cable tension and which has substantially identical readings for identically tauten'ed cables of similar characteristics regardless of known variations in diameters thereof.

In the accompanying drawings forming part of this description,

Fig.1 represents a side elevation of the instrument according to a preferred embodiment thereof in engagement with a cable shown in section.

Fig. 2 represents a section on line 2--2 of Fig. 1.

Fig. 3 represents a plan of the instrument of Fig. 1.

Fig. 4 represents a diagrammatic elevation of the operative portions of the dial and snubber assembly in operative association with a fragment of the friction release plunger.

In the-preferred embodiment there is provided an upper or primary lever or frame member 10 having a handle portion 9, and which is enlarged and effectively bifurcated or slotted in the substantial center, to form spaced side members- II and I2. The latter are respectively provided onthe outer surfaces with the integral bosses l3 and I4, suitably apertured as'at 15, to form a pivotal bearing for the transverse axis pin l6, which extends through and on each side laterally beyond the bosses to receive the snubber or frictional-release-lever to be described.

The lever I0 extends downwardly beyond the enlarged slotted central portion and merges integrally, preferably, into the lower jaw H, which ;is suitably reinforced as by the integral web [8 on the lower surface transverse of the lever. The upper face of the lower jaw l1 carries at each end the spaced cable-receiving angularly grooved members 20 and 2|, respectively, the

grooves 22 of which face or present upwardly to receive .and center cables of a wide range of sizes. An illustrative cable is indicated at 8. If desired, grooved rollers or the like may be substituted for the fixed guide members shown. A lower or secondary lever or frame member 23 is provided, narrow enough tobe insertable between the spaced lateral walls I I and [2, of the upper or primary member or lever, and has lateral bosses 24 and 25, the outer faces of which are of such relative spacing as to flt slidably within the spaced walls I l and I2 of the primary against a taut cable from a point spaced from 5 leverand the lever 23 and aligned bosses 24 and and may materially'affect the'readings'.

21 and member 28 comprise the other or upper,

jaw of the instrument, opposed to jaw ,The

center of groove 30 of block 28 is aligned laterally with the centers of the grooves 22 of thecomplemental blocks 20 and 2|, when the frames are swung on axis l6 so as to cause such'alignment.

The beam or cantilever member 21 is clamped at its inner anchored end to the'frame or lever 23 by the inner anchored end 3| bf the goose neck arm 32 for the recording indicator 34 to be described. Arm'32 overlying the beam, is cut away underneath as at 29, to permit the beam to flex, and the cut-away portion terminates in a the out-motion of the indicator, in response to the imposition of a load by which the beam is deflected, be free of the frictional restraint of the snubber, and this is secured and controlled by plunger 35 deflecting spring 69 and thus relieving friction cable 59. To this end a bracket arm 36 is mounted on the housing of the register, having a guide hole in general or substantial alignment with the plunger 35, within which area 31 i slidably guidable, and the latter has a downwardly presenting cam 38, having a sloping or inclined face in engagement with the end of plunger35, in position to force it radially inshoulder 33, marking the forward end of the terminal 3| of 'the'goose-neek inits contact with and overlyingthe beam 21, which may be angular or rounded, to define an effective fulcrum about which the beam deflects, aswill be clear. The outer or free end of the goose neck 32, rig1d 1y carries the dial instrument or'indicato'r 34, preferably having a spring-loaded'centrallypiw oted movable pointer 39 controlled by thej'generally vertical load-receiving plunger |9. Obviously, any sort of indicator may be used-and it may be disposed in any p'os'ition'so long as it is so located as to be actuated as a result of flexing of the beam and movement of the freeend thereof. The indicator is so mounted that the plunger end-is arranged toabut and to ride upon the free end of the 'cantilever b'eam 21 with 'whichit has a zero setting of contact when the beaniis unstressed and unflexed." Any' 'flexing upwardly actuates the plunger.' 'The pointer '39 is moved about the center'of thedial in response to upward'motions of theplunger; slidingfreely portion of i the goose-neck support 32. r Although it is contemplated that in ce'rtai'n'instances sufficient accuracy may be achieved by'a double pointer indicator, comprising a master pointer and a dragged lpoin'ter, the latter of which remains "at the position to whichit is moved by the master pointer; inresponse to a beam-deflection and subsequent release of deflection'and 'zero resetting of the'masterpointer, thefriction involved is substantialand frequently 'inconstant It is preferred to use adial pointer whichmoves' angularly' in'responsejto load and which is selectively either free or under the controlled rethrough the appropriately spacedor apertured 'str'aint of alsnubber or imposed friction such as flexible'b'ralge cord or thelike 59, which latter, in one form of indicator as shownin Fig. 4," is normally resiliently effective by'spring 69jupon the pc'lil'rilie 1"" 3 to retain it in its adjuste'd D051- tion. "Ihis serves'as a recorder of the'established'ltensionreading, and the s'nubb'er is arrangedto be released or thrown out of action by inward radial motion of the small spring wardly of the housing when the rod 31 is forced downwardly. To facilitate this action, the lower ,or secondary lever or frame 23 has a gripping piece 40 upon which all but one of the operator's fingers of one hand are disposed in gripping, manipulating and actuating the tool. The front end of the gripping piece terminates in rearwardly spaced relation to an apertured lug or ear i4|; integral with the lower lever. Lug 4| anchors the rear end. of a tension-spring 42, anchored at the front to an apertured web 43 of the lower end of the upper lever, to urge the jaws apart, until stops onv terminal 3| of gooseneck32 engage therespective lugs or arms H and 12, as will'be clear; In the space 44 between gripping piece 4|! and lug 4|, there is provided the transverse finger element 45, merging at one side of lever'23 into the forwardly extending lever 46, having an aperture and being pivotally mounted on one'end of the axis pin l6, outside of the boss l4, and terminating in the forward and laterally'extending end 41, bent from arm 46 so a to be substantially aligned with the lower end ofz'lthe ro'd'31, whichit pivotally engages. To strengthenthe friction release lever 46 in its pivotal relation, it is preferred to provide a for- .ward cross-element or member 49 leading to a rearwardly extending arm 48 pivotally mounted onifthe' other end of axis pin "5 adjacent tothe external boss |3 of the upper lever.

:An-"important'attribute of this'invention lies in its adaptability to proper and correct use with .various diameters or conditions of cable, called herein deflectioncharacteristics. This is ex- ,peditiously-efiected by providing preferably topressed plunger 35; Upon the inward movement thereof, radially'of the housing or the instrument," the frictional snub or drag is removed. It is important in securing exact readings thatward or at the rear ends-of the respective levers, and preferably, although not essentially, on the opposite side of'the pivot from the jaw, an adjustable stop, which may comprise a cam, screw, :wedge or the like. Illustratively only, it may Icomprise a cam device 50 which is pivoted to or on one lever'with a variable degree of friction, :as at 5|, and has an operative face or edge pro- Vided for instance with angular notches, illus- Etratively respectively 52, 53 and 54 etc., for in- ,stance; arranged selectively according to the setting of-the cam and the lever to abut and be z-st'opped upon the shoulder55 of a block 56 on -the' other leverysuch as lever 23. Obviously, 'the-cam may be mounted on either lever and at :any' pos'ition'thereon. The cam piece in the i1- :lustrativeform is swungfurther toward the rear -toen'able the uppernotchesto engage the stop, and "is' swung forwardly'to engage the lower notches or'other stop setting with the stop. The notch'e'sare so located and proportioned to the *diamete'rand elasticity of the cable beingengaged (its deflection characteristics) that the deflection'of'the beam during operation of the instrument due to the tension 'of the given cable is substantially the same as for cables of' other -diameters but of the same characteristics and Theewhh size 2. 5 t e e r e1 vqh eese e We:

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spective members to' engage a cable and thus to deflect the elastic element, the plunger being moved relative to the indicator-it d actuate same to measure the deflection of the element and thus the tension of such cable, means constantly mounted on the tensiometer duringpadjustments operative toimpose predetermined variablelimits on the relative motions of the levers to causethe reading of the indicator to be accurate for various predetermined deflection characteristics of cable, a friction drag snubber'operatively associated in manually controlled selective engage,- ment or disengagement with the indicatoninearis for disengaging the snubber dming defiectio'n measuring movement of the indicator to' avoid inaccuracies'of readings due to friction, and

means engagingthe snubber and indicator to temporarily maintain the indicator at the established reading after release of the able.

6. A tension meter comprising a pair of relatively movable cable engaging elements; one ele- ;ment comprising spaced cable contact devices and the other element comprising a deflection beam having a free end, means on the free end of the beam for engaging a cable to-be tested, means for urging'the elements together eifective on the beam at a point spaced iromthe freeend thereof to cause the deflection of the beam relative cable;

to such taintass function of tension in such cable, means including a'movable' indicator for measuring th'e deflection of the beamas a measur'of 'tensionof such cable, means constantly mounted on the tensiometerduring adjustments for 'proportioning the deflectionpotentialities of the beam to the deflection characteristics oi the cable to e tested/a friction drag snubber op 'erati'vely associated inmanu'ally'controlled selective engagement or disengagement with the indicator,means for-disengaging thesmibber durmg deflection measuring movement of the indicator to avoid inaccuracies of readings: due to friction, and means engaging the snubber and indicatort o temporarily maintain the indicator at'the established reading after release of the 7;. A tensionrmeter comprising alever, a pair of relatively spaced "cable-contacting members mounted' rigidlyon one end of the lever; a sec ond'leve'r pivoted tothe-first lever, a plunger operated indicator mounted on the second lever, a plungerextending from the 'indicatorltoward a lineflextending between the members, an elastic elementmounted rigidly at one end to the second lever and extending under theplunger, a

cablecontacting element mounted on the elastic member and presenting toward and located be:- tween the flrst'mentionedspaced members, the

relative movement of the levers on their pivot causing the respective'mer'nbers to engage a cable and thus to deflect the elastic; element. the plunger being moved relative to the indicator to actuate same to measure the deflection of the element and thus the tension of such cable, a friction drag snubber operatively associated in manually controlled selective engagement or disengagement with the indicator, means for 'disengaging the snubber during deflection measuring movement of the indicator to avoid inaccuracies of readings due to friction, andrneans engaging the snubber and indicatorto temporarily maintain the indicator at the established reading after release of the cable. 8. Atension meter comprising a pair of pivoted leversforming a' pair of plier jaws, one of the plier jaws comprising a pair of spacedcable recalving elements, and the other plier jaw comprising a cantilever member including a cable receiving element comprising an' extension of a lever, arranged to de'flectlunder pressure from the pivoted levers when the cable-receiving elements are in pressing contact against a taut cable, means including a movable indicator for measuring the deflection of the cantilever member as a function or tension in the cable, a friction drag snubber operatively' associated in manually controlled selective e gagement or disengagement with the indicator, means for disengagingthe snubber during deflection measuring movement of the indicator, to avoid inaccuracies of readings due to friction, and means. engaging the snubber and indicator totemporarily maintain the indicator at theestablished reading after release of the cable. v a 1 p 9. A tension meter comprising a pair of relatively movable cable engaging elements, one element comprising spaced cable contact devices andthe other element comprising a deflection beam having a free end, meanson the free end of the beamffor' engaging a cable to be tested, means for urging the elements together effective on thebeam at a point spaced from the free end 'thereof'to causethe deflection of the beam relative to such point as a function of tension in 5 the cable.

of the indicator to avoid inaccuracies of readings due to friction, and means engaging the snubber and indicator to temporarily maintain the indicator at the established reading after release of HENRY J. SANG. 

